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Among the necessary mineral required in the body, some are classified as trace minerals. They are needed in trace amounts to carry out important functions in the body.
Zinc is one such mineral necessary in the maintenance of body functions such as:
- Cell division
- Normal growth
- Creation of new DNA in the cells that multiply
- Genetic expression
- Proper functioning of the immune system
- Growth and development of a healthy fetus during pregnancy
- Creating new proteins (non-essential amino acids)
- Metabolization and proper uptake of carbohydrates
Therefore, maintaining a sufficient level of zinc is vital for a healthy functioning body. (1)
Recommended Dietary Allowance of Zinc
The recommended dietary daily allowance (RDA) is the amount of a certain mineral that is required to maintain necessary functions. This limit is set by health bodies around the world, and figures can vary based on ethnicity, geographic location, age, and gender.
Having lower levels of zinc than required can lead to health problems.
Signs and Symptoms of Zinc Deficiency
Various signs and symptoms of zinc deficiency can include the following.
1. Impaired physical growth
Growth retardation, especially linear growth (height), and improper weight gain are common characteristics of zinc deficiency in children.
Several studies aimed at studying the effect of zinc supplementation in young children with growth retardation concluded that sufficient zinc supplementation aided growth when compared to a placebo. (4)
2. Delayed mental and psychomotor development
It is no secret that proper nutrition is a must for brain growth and development. Animal studies have proven that zinc deficiency in early life can hinder normal brain development and cognitive functions such as learning, memory, and attention. (5)
Zinc provides increased resistance to infections as it supports the immune system. Therefore, zinc deficiency can make you susceptible to intestinal infections and can be a major cause of diarrhea.
Research has shown that supplementation with zinc reduced the duration of diarrhea and was important in reducing infection-related deaths in infants. Zinc also improves the absorption of electrolytes and nutrients through the intestine, preventing the risk of dehydration during episodes of diarrhea. (6)(7)
Studies also suggest the role of zinc supplementation (plus oral rehydration therapy) in reducing the duration and severity of acute and persistent childhood diarrhea. (8)
4. Reduced immunity
Since zinc plays a major role in the immune system, zinc-deficient populations may experience increased susceptibility to a variety of disease-causing microorganisms. This is because zinc is crucial for the development and functioning of cells that mediate immune responses such as neutrophils and natural killer cells. (9)
Various animal and human studies have been performed to understand the role of zinc in resistance to infectious diseases. Zinc-deficient animals have shown a decrease in immune responses and are therefore very much susceptible to various infectious agents such as: (10)
- Herpes simplex virus
- Mycobacterium tuberculosis
- Candida albicans
- Plasmodium yoelii
5. Appetite issues and eating disorders
Anorexia nervosa is an eating disorder characterized by an alarmingly low body weight due to the fear of gaining weight and having a wrong perception of weight. People with anorexia strictly restrict the amount of food they consume and can even control calorie intake by forceful vomiting after eating or excessively exercising. (11)
6. Poor vision and other eye issues
The American Optometric Association states that zinc is essential for vision and deficiency can cause poor vision and cloudy cataracts.
According to a study, the odds of developing age-related macular degeneration were significantly reduced by zinc and antioxidants plus zinc. (14)
7. Impaired memory
A deficiency of zinc has been linked to impaired memory. The mechanism behind this is unclear, but according to a study, zinc was found to be essential for memory formation in animal models. It also explained the possibility that zinc can have an impact on learning and memory.
One possible reason for this is that zinc acts through a pathway that is crucial for the development of many forms of memory, including fear conditioning and spatial memory. (15)
8. Hair loss
Zinc also plays a role in the maintenance of healthy tresses. Studies have demonstrated alopecia (or premature hair loss) to be a sign of zinc deficiency.
A review of multiple studies found lower zinc levels in people suffering from alopecia when compared to the healthy control group. In one of these studies, 50 mg of zinc gluconate for 12 weeks led to an improvement in patients with alopecia, suggesting its use to be beneficial. (16)
ALSO READ: 10 Foods to Prevent Hair Loss
9. Delayed sexual maturity
Zinc supplementation in postmenopausal women has been found to improve: (17)
- Sexual desire
- Vaginal moisture
- Pain during intercourse
- Overall sexual function
Serum zinc levels also influence stages of sexual maturation and mean age at menarche (onset of periods and therefore reproductive age). Naturally, decreased serum zinc levels or deficiency can delay sexual maturation in children. (18)
10. Taste and smell disorders
In a study of 1,500 patients with a taste disorder, improvements were seen in the patients after zinc administration. A significant part of these cases was disturbances of the taste buds caused by zinc deficiency. Furthermore, researchers established that zinc deficiency may cause smell disorders in patients with olfactory epithelium disorders. (19)
A decrease in zinc levels was also observed in COVID-19 patients with taste/smell disorder, suggesting zinc supplementation to be a useful remedy in restoring taste and smell. (20)
11. Poor nail health
Nails can be a gateway to your nutritional profile as many nutritional deficiencies often show up on nails.
Research points to zinc deficiency as one of the causes of poor nail health, which can include the following signs: (21)
- Paronychia – infection of tissues around the nail
- Cuticle inflammation
- Beau lines of white transverse bands or Muehrcke’s nails
12. Skin disorders
Your skin is the third-most zinc-abundant tissue in the body. Therefore, zinc deficiency may be greatly associated with the development of skin disorders. (22)
According to the Australasian College of Dermatologists, zinc deficiency can cause skin changes that appear to be similar to atopic dermatitis (eczema) but such skin manifestations (that are due to zinc deficiency) do not show much improvement when dealt with topical steroids and moisturizers.
Zinc deficiency can make the skin look cracked and fissured.
13. Irritability and psychological disorders
There is a wide range of psychological signs of zinc deficiency as zinc is involved in various biological processes. Zinc deficiency may lead to: (23)
- Emotional instability
- Increased anxiety
- Deficits in social behavior
Moreover, lower serum levels of zinc have been documented in psychological disorders such as: (23)
- Autism spectrum disorders (ASD)
- Attention-deficit hyperactivity disorder (ADHD)
- Mood disorders
- Schizophrenia (SCZ)
Treating Zinc Deficiency Via Diet
Zinc deficiency can be solved with an improved diet. You can get the recommended amounts of zinc by consuming the following:
- Nuts and seeds
- Whole grains
- Fortified breakfast cereals
Note: Only take zinc supplementation after consulting a doctor as a high intake of zinc can lead to zinc toxicity.
Most-Asked Questions About Zinc Deficiency
Who is at risk of zinc deficiency?
Zinc deficiency is rare. The following groups of people are more likely than others to have trouble getting enough zinc:
- Pregnant women
- People with digestive disorders
- People with chronic liver disease
- People with chronic kidney disease
- People who experience prolonged diarrhea
Can too much zinc be harmful?
Yes, zinc can be harmful if you take too much supplementation. Large amounts of zinc may cause:
- Poor appetite
- Stomach pain
Zinc is a nutritionally essential mineral. It is an essential trace element because various body functions are zinc dependent. Zinc deficiency is persistent around the world, with approximately 2 billion people affected by it.
Making sure you have a sufficient amount of zinc in your body is extremely important to avoid health risks and complications.